This invention concerns nailing apparatus for use in making cable reel flanges or the like. By the expression "cable reel flanges or the like" is intended any workpiece which requires the insertion thereinto of a pattern of nails which is repeated in segments of the workpiece such that the workpiece can have the nails inserted by being turned about an axis to bring said segments successively into position opposite nail inserting means arranged to insert said pattern of nails. Such workpieces are generally circular or, as in the case of cable reel flanges, intended to be cut to a circular shape. Although the apparatus to which the invention is applicable is referred to as "nailing apparatus," it is to be understood that the invention is equally applicable to apparatus intended to insert other types of fastener, for example screws and staples.
In the manufacture of cable reel flanges, it is customary for an assembly consisting of a plurality of layers of wooden planks, each layer comprising a number of planks, to be nailed together, the planks being of various lengths according to their position in the assembly so that they form an assembly having a general shape which can, subsequently to the nailing operation, be cut into a circular shape with a minimum of waste. The phrase "cable reel flange" where used herein is to be understood as including not only finished cable reel flanges, for instance as herein illustrated, but also such flanges in the course of their manufacture, and especially including an assembly as referred to above.
For nailing cable reel flanges together, it is customary to use a nailing apparatus comprising a work support table on a surface of which a cable reel flange to be operated upon can be supported, fastener driving means, and means providing a turning centre about which a cable reel flange supported on the work support table can be indexed, in order to present successive portions of the cable reel flange to the fastener driving means. Usually the fastener driving means includes a plurality of hammer arrangements and nail feed arrangements, which are arranged in a segmental pattern so that the flange can be nailed progressively in segments by turning it between successive nailing operations about the turning center.
Two different means providing a turning center are used conventionally in such nailing apparatus, a first of which is a so-called spike, which is driven into the under-side of the flange, at a central point thereof, and the flange is thus impaled on the spike, while the other is a locating element in the form of a so-called drum locating pin, which is constructed to enable insertion into an aperture formed therefor in a central portion of the cable reel flange. Where a spike is used, customarily a further spike is aligned immediately above and depends downwardly, this further spike serving to center the flange in a desired position prior to its being impaled on the lower spike, and the further spike itself also being driven into the flange so that the two spikes form a turning center.
The provision of a turning center using either of the locating elements mentioned above does not, however, in itself facilitate the turning of the flange on the work support table. Especially in the case of large cable reel flanges, the flanges are both cumbersome and heavy to handle, and it is often the case that two or even three workers are required to index the flange round, even though only one operative is required for controlling the operation of the apparatus. In order to facilitate such indexing, it has been the practice to provide, spaced apart over the surface of the work support table, a plurality of work-supporting ball members, each accommodated in a housing therefor, such ball members projecting slightly above the surface of the work support table and being capable of revolving within their housings in any desired direction. These ball members, however, are restrained against heightwise movement so that each nailing operation causes the flange to be pressed on to the upstanding portions of the ball members with a result that the surface of the flange is dented by the ball members, thus rendering it more difficult to initiate further indexing of the flange. Furthermore, the ball members are not provided in an area across the width of the flange corresponding to the nailing area, so that a substantial part of the flange is unsupported by ball members entirely.